The upper level pattern the second week of January had a very strong long-wave trough across the Great Lakes region that basically caused significant arctic air to invade the upper Midwest.
A deep snow pack and several minor snowfall events prior to this arctic outbreak allowed for little modification of this air mass as it dived southward. Temperatures dropped below zero and stayed below zero for the majority of the outbreak.
In addition to the low temperatures, brisk winds of 10 to 20 mph caused wind chill values to drop into the 40 to 60 below range. Some of the coldest wind chill values are as follows; Glenwood at -56, Morris at -56, Alexandria at -51, Benson at -51, Granite Falls at -51, Appleton at -49, Redwood Falls at -49, Willmar at -49, Fairmont at -48, St. Cloud at -48, and St. James at -47.